Roentgenium-280

Properties and data of the isotope ²⁸⁰Rg.

Content

General data

Name of the isotope:Roentgenium-280; Rg-280Symbol:²⁸⁰Rg or 280111RgMass number A:280 (= number of nucleons)Atomic number Z:111 (= number of protons)Neutrons N:169Isotopic mass:280.16520(57) u (atomic weight of Roentgenium-280)Nuclide mass:280.104318 u (calculated nuclear mass without electrons)Mass excess:153.88281 MeVMass defect:2.167749356 u (per nucleus)Nuclear binding energy:2019.24551862 MeV (per nucleus)
7.21159114 MeV (average binding energy per nucleon)Separation energy:S_N = 5.907(679) MeV (first neutron)
S_P = 2.427(806) MeV (first proton)Half-life:4.4 sDecay constant λ:0.15753345012726 s^-1Specific activity α:3.388173667207 × 10⁺²⁰ Bq g^-1
9157226127.5886 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2004

Radioactive Decay

Half-life T_½ = 4.4 s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁷⁶Mt	ca. 100 %	10.149(10) MeV

Parent Nuclides

Direct parent isotope is: ²⁸⁴Nh.

Occurrence

Comparison of the natural Roentgenium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Roentgenium Isotopic mixture	280.16447 u	100 %
Isotope ²⁸⁰Rg	280.16520(57) u	100 %	4.4 s

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 169) and isobaric (same nucleon number A = 280) with Roentgenium-280. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.